Motor operated compressor

ABSTRACT

A motor operated compressor has a housing having a motor chamber and a driving motor located in the motor chamber. The compressor also has a first scroll and a second scroll coupled to the first scroll to form a compression chamber. A rotating shaft is coupled to a rotor of the driving motor and eccentrically coupled to the first scroll. A rear housing of the motor forms a discharge chamber with the second scroll. A shaft receiving portion that radially supports the rotating shaft is located either in the second scroll or in the rear housing. An oil supply guide flow path located either in the second scroll or in the rear housing connects the discharge chamber and the shaft receiving portion. A decompression member inserted into the oil supply guide flow path, reduces a pressure of a fluid passing through the oil supply guide flow path.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2018-0142073, filed on Nov. 16, 2018, the contents of which are incorporated by reference herein in their entirety.

BACKGROUND 1. Field

The present disclosure relates to a motor operated compressor.

2. Background

A motor operated compressor of a scroll compression type suitable for an operation of a high compression ratio is widely known. A scroll type motor operated compressor (hereinafter abbreviated as a motor operated compressor) includes a motor unit as a driving motor inside a closed casing, a compression unit including a fixed scroll and an orbiting scroll installed on one side of the motor unit. The compression unit is connected to a rotational shaft so that a rotational force of the motor unit is transmitted to the compression unit.

This motor operated compressor separates oil from a refrigerant discharged from the compression unit and supplies a part of the separated oil to a back pressure chamber or a bearing surface. Prior art 1 (Japanese Laid-Open Patent Application No. 2013-155643, Publication date: 2013 Aug. 15) shows an example of a dualized oil supply passage and prior art 2 (Japanese Laid-Open Patent Application No. 2013-100812, Publication date: 2013 May 23) shows an example of having a unified oil supply passage.

The motor operated compressor according to Prior Art 1 includes a first oil supply passage through which oil stored in an oil storage chamber is decompressed in a back pressure spring plate and then supplied to a main bearing and a sub-bearing and a second oil supply passage through which oil of a compression chamber is supplied to an orbiting bearing through an orbiting wrap and then moves to a motor chamber through a back pressure chamber.

The motor operated compressor according to Prior Art 2 includes one oil supply passage through which oil in a compression chamber or a discharge chamber is supplied to an orbiting bearing, supplied to a main bearing through a back pressure chamber, supplied to a sub-bearing through a passage in a rotational shaft, and then discharged to a motor chamber.

In the motor operated compressors described above, the oil is separated from the high-pressure refrigerant discharged from the compression chamber, and the separated high-pressure oil is supplied to the bearing or back-pressure chamber so that the oil is reduced to an appropriate pressure, before being supplied to the bearing or back pressure chamber, and supplied. To this end, the oil supply passage is elongated so that the oil is reduced in pressure while passing through the elongated oil supply passage, or the oil supply passage is formed at a wrap so that the oil is reduced in pressure while passing through the oil supply passage provided in the orbiting wrap.

However, in the conventional motor operated compressors as described above, when the oil supply passage is long, the oil supply passage becomes complicated and oil may not be supplied quickly to the bearing surface or the back pressure chamber. Further, since the oil supply passages provided in each of the plurality of members must be connected to each other, machining errors or assembly errors may occur, which may make it difficult to form the oil supply passages. Also, if the machined oil supply passages do not match up during assembly, the oil supply passage may be narrowed and clogged by a foreign material, and oil may not be supplied smoothly. Further, the oil may not be smoothly supplied to the bearing surface or a pressure distribution in the back pressure chamber may become uneven, which in turn may make the behavior of the orbiting scroll unstable and lower the compression efficiency.

In addition, in the conventional motor operated compressors, when the oil supply passage is formed in the orbiting wrap, the orbiting wrap and a disk plate part of the fixed scroll opposing the orbiting wrap are separated and the oil is selectively introduced. As a result, the oil may not be quickly supplied to the back pressure chamber and the back pressure may become unstable, which may reduce compression efficiency as described above. In addition, since the oil supply passage must be formed as a fine hole in the orbiting wrap and which may require relatively precise machining, the orbiting wrap may be deformed and reliability of the compressor may be deteriorated. Further, as the oil supply passage directly communicates with the compression chamber, the effective volume of the compression chamber may be reduced as the oil flows back to the compression chamber from the back pressure chamber, and foreign materials in the back pressure chamber may easily flow into the compression chamber.

SUMMARY

Therefore, an aspect of the detailed description is to provide a motor operated compressor capable of increasing a decompression effect, while a decompression flow path is formed to be short and simple.

Further, another aspect of the detailed description is to provide a motor operated compressor capable of preventing a cross-sectional area of a decompression flow path from becoming excessively narrowed due to machining errors or assembly errors.

Still further, another aspect of the detailed description is to provide a motor operated compressor in which a decompression flow path is formed in a single member.

Further, another aspect of the detailed description is to provide a motor operated compressor in which an effective length of a decompression flow path is secured to maintain a decompression effect constant and maintain a pressure in a back pressure chamber constant to suppress a compression loss while stabilizing a behavior of an orbiting scroll.

Further, another aspect of the detailed description is to provide a motor operated compressor in which oil is quickly and stably supplied to a bearing surface, a compression chamber, or a back pressure chamber, thereby improving reliability and compression efficiency.

Further, another aspect of the detailed description is to provide a motor operated compressor in which a decompression flow path is always maintained in an opened state.

Still further, another aspect of the detailed description is to provide a motor operated compressor in which backflow of oil to a compression chamber through a decompression flow path.

Further, another aspect of the detailed description is to provide a motor operated compressor in which an axial load applied to a rotating shaft is reduced, thereby increasing lifespan of an axial bearing and reducing a friction loss in an axial direction.

Further, another aspect of the detailed description is to provide a motor operated compressor in which one end of a rotating shaft is prevented from being exposed to a discharge chamber so that a load applied to the rotating shaft by the oil of a discharge pressure in an axial direction may be reduced.

To achieve these and other advantages and in accordance with the purpose of this disclosure, as embodied and broadly described herein, a motor operated compressor includes: an orbiting scroll; a fixed scroll coupled to the orbiting scroll and forming a compression chamber; a rotating shaft rotatably coupled through the orbiting scroll and the fixed scroll; a shaft receiving portion formed at the fixed scroll or a housing coupled to the fixed scroll and allowing the rotating shaft to be inserted and supported in a radial direction; an oil supply guide flow path formed to penetrate through a side wall surface of the shaft receiving portion in the radial direction and communicating with the inside of the shaft receiving portion; and a decompression member inserted into the oil supply guide flow path, wherein the oil supply guide flow path is formed to have a plurality of axial centers.

The decompression member may be fixed and coupled to the oil supply guide flow path in the axial direction.

A decompression flow path may be formed inside the decompression member.

To achieve these and other advantages and in accordance with the purpose of this disclosure, as embodied and broadly described herein, a motor operated compressor includes: a housing having a motor chamber; a driving motor provided in the motor chamber of the housing; a rotating shaft coupled to a rotor of the driving motor; a first scroll allowing the rotating shaft to be eccentrically coupled by penetrating therethrough in an axial direction and performing an orbiting motion by the rotating shaft; a second scroll coupled to the first scroll, forming a compression chamber together with the first scroll, and allowing the rotating shaft penetrating through the first scroll to be rotatably inserted and coupled; a rear housing forming a discharge chamber together with the second scroll; a shaft receiving portion provided in the second scroll or the rear housing and supporting the rotating shaft in the radial direction; an oil supply guide flow path provided in the second scroll or the rear housing and allowing the discharge chamber and the inside of the shaft receiving portion to communicate with each other; and a decompression member inserted into the oil supply guide flow path and reducing a pressure of a fluid passing through the oil supply guide flow path.

An oil supply protrusion portion may be formed to extend in the radial direction from the shaft receiving portion, and the oil supply guide flow path may be formed to penetrate through the oil supply protrusion portion in the radial direction.

Also, the oil supply guide flow path may be opened at both ends and a first end communicating with the discharge chamber may form an oil supply inlet and a second end communicating with the inside of the shaft receiving portion may form an oil supply outlet, a decompression member accommodating portion into which the decompression member is inserted may be formed between the oil supply inlet and the oil supply outlet, a radial sectional area of the decompression member accommodating portion may be larger than a radial sectional area of the decompression member so that the decompression flow path is formed between an outer circumferential surface of the decompression member and an inner circumferential surface of the decompression member accommodating portion, and the oil supply inlet, the decompression member accommodating portion, and the oil supply outlet may be formed to successively communicate with each other.

The oil supply outlet may be formed to be eccentric with respect to the decompression member accommodating portion.

Also, an axial length of the decompression member accommodating portion may be larger than an axial length of the decompression member.

Also, the axial length of the decompression member accommodating portion may be equal to the axial length of the decompression member.

Also, a decompression member support portion supporting the decompression member in the axial direction may be formed to be stepped between the oil supply outlet and the first end of the decompression member accommodating portion, and an axial center of the decompression member support portion may be formed to be eccentric with respect to an axial center of the oil supply outlet.

The oil supply outlet may be formed on the same line with the oil supply inlet in the axial direction.

Also, the decompression member may be inserted into the decompression member accommodating portion so as to be fixed and coupled.

A decompression passage may be formed to penetrate through a central portion of the decompression member along the axial direction, and the decompression passage may communicate with the oil supply outlet.

The decompression member may be formed of a material having hardness lower than that of a member to which the decompression member is coupled.

A support protrusion portion extending in a radial direction may be formed at one end of the decompression member, a support recess portion supporting the support protrusion portion in the axial direction may be formed at an end portion of the decompression member accommodating portion adjacent to the oil supply inlet, and the oil supply outlet and an end portion of the decompression member facing the oil supply outlet may be spaced apart from each other to form a communicating space allowing the decompression flow path and the oil supply outlet to communicate with each other.

Also, a communicating space portion may be formed toward the oil supply outlet at an end portion of the decompression member facing the oil supply outlet.

A foreign material blocking member for blocking a foreign material may be further provided at the oil supply guide flow path, and a plurality of oil supply through holes may be formed at the foreign material blocking member.

The foreign material blocking member may be located to be adjacent to the discharge chamber based on the decompression member.

A sectional area of the oil supply through hole may be formed to be smaller than or equal to a sectional area between an inner circumferential surface of the oil supply guide flow path and an outer circumferential surface of the decompression member.

In the motor operated compressor according to the present disclosure, the oil supply protrusion portion having the oil supply guide flow path is formed in the fixed scroll forming the discharge chamber or the rear housing, and the decompression flow path is formed by inserting the decompression member into the oil supply guide flow path, and thus, the decompression flow path may be formed to be short and simple and a length of the decompression member and a sectional area of the decompression flow path may be easily adjusted to increase a decompression effect.

Further, since the decompression flow path is formed at only one of the fixed scroll and the rear housing, a machining error or an assembly error may be reduced, thereby preventing the sectional area of the decompression flow path from being excessively narrowed, thus easily adjusting a decompression degree and making a pressure dispersion uniform.

Further, since the inlet and the outlet of the oil supply guide flow path are formed on both sides of the decompression member in the length direction, a uniform effective length of the decompression flow path may be secured. In addition, by uniformly maintaining the decompression effect to constantly maintain the pressure of the back pressure chamber, a behavior of the orbiting scroll may be stabilized and a leakage between compression chambers is suppressed, reducing a compression loss.

Further, in the motor operated compressor according to the present disclosure, since the outlet of the oil supply guide flow path is formed to be located eccentrically with respect to the decompression member accommodating portion, the outlet of the oil supply guide flow path may be maintained to always communicate with the decompression flow path. Accordingly, the oil may be quickly and stably supplied to the bearing surface, the compression chamber, or the back pressure chamber, thereby improving reliability and compression efficiency.

Further, since the decompression member is inserted into the oil supply guide flow path to form the decompression flow path, the orbiting scroll or the fixed scroll may be easily machined and both scrolls may be driven stably, thereby improving reliability of the compressor.

Furthermore, as the decompression flow path is separated from the compression chamber, it is possible to prevent the oil from flowing back to the compression chamber through the decompression flow path.

Further, in the motor operated compressor according to the present disclosure, since the decompression flow path is located on a front side than the oil accommodating space in which the rotating shaft is accommodated, an axial load to the rotating shaft in the axial direction may be reduced. Accordingly, the rotating shaft may be prevented from being exposed to the discharge pressure, thereby reducing the axial load applied to the rotating shaft, extending a service life of the bearing supporting the rotating shaft in the axial direction, and reducing a friction loss.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an appearance of a motor operated compressor according to an exemplary embodiment of the present disclosure.

FIG. 2 is a perspective view of the motor operated compressor of FIG. 1.

FIG. 3 is a cross-sectional view showing the inside of the motor operated compressor of FIG. 1.

FIG. 4 is a perspective view of a decompression device shown in FIG. 3.

FIG. 5 is a cross-sectional view of the decompression device which is assembled shown in FIG. 4.

FIG. 6 is a cross-sectional view taken along line “V-V” of FIG. 5, for explaining relative positions of an oil supply outlet and a decompression member accommodation portion.

FIG. 7A is a schematic view for explaining a position of a decompression member during operation of the decompression device according to FIG. 5.

FIG. 7B is a cross-sectional view taken along line “VI-VI” in FIG. 7A.

FIG. 8 is a cross-sectional view showing another exemplary embodiment of a decompression member according to FIG. 3.

FIG. 9 is a cross-sectional view taken along line “VII-VII” in FIG. 8.

FIG. 10 is a cross-sectional view showing another exemplary embodiment of the decompression member according to FIG. 3.

FIG. 11 is a cross-sectional view taken along line “VIII-VIII” in FIG. 10.

FIG. 12 is a cross-sectional view showing another exemplary embodiment of a decompression device according to the present disclosure.

FIG. 13 is a cross-sectional view taken along line “IX-IX” in FIG. 12.

FIG. 14 is a cross-sectional view showing another exemplary embodiment for fixing a decompression member in a decompression device according to the present disclosure.

FIG. 15 is a cross-sectional view taken along line “X-X” in FIG. 14.

FIG. 16 is a cross-sectional view showing an exemplary embodiment in which a decompression member is in a free state in a decompression device according to the present disclosure.

FIG. 17 is a cross-sectional view taken along line “XI-XI” in FIG. 16.

FIG. 18 is a cross-sectional view showing a foreign material blocking member provided at an oil supply inlet in a motor operated compressor according to the present disclosure.

FIG. 19 is a cross-sectional view showing an exemplary embodiment in which a decompression device according to the present embodiment is installed in a rear housing.

DETAILED DESCRIPTION

Hereinafter, a motor operated compressor according to the present disclosure will be described in detail with reference to an exemplary embodiment shown in the accompanying drawings.

FIG. 1 is a perspective view showing an appearance of a motor operated compressor according to an exemplary embodiment of the present disclosure, FIG. 2 is an exploded perspective view of the motor operated compressor according to FIG. 1, and FIG. 3 is a cross-sectional view showing the inside of the motor operated compressor according to FIG. 1.

Referring to these drawings, a scroll type motor operated compressor driven by a motor (hereinafter abbreviated as a motor operated compressor) according to the disclosed exemplary embodiment may include a compressor module 101 for compressing a refrigerant and an inverter module 201 coupled to a front side of the compressor module 101 to control driving of the compressor module 101. The compressor module 101 and the inverter module 201 may be assembled successively, or may be independently manufactured and assembled. In this embodiment, the latter will be described as a representative example. However, the compressor module and the inverter module may be independently manufactured and assembled as a type in which the former and the latter are mixed.

The compressor module 101 may include a main housing 110 having an internal space forming a motor chamber S1 and an intake port 111 communicating with the motor chamber S1, a driving motor 120 as a motor unit fixed to the motor chamber S1 of the main housing 110, a compression unit 105 provided at one side of the driving motor 120 outside the main housing 110 and compressing a refrigerant using a rotational force of the driving motor 120; and a rear housing 160 coupled to the other side of the compression unit 105 to form a discharge chamber S2.

The main housing 110 may be disposed in a horizontal direction with respect to the ground, the driving motor 120 and the compression unit 105 may be arranged along the horizontal direction, the driving motor 120 may be disposed on a front side, and the compression unit 105 may be installed on a rear side. For convenience, the left side of FIG. 3 will be designated as the front side and the right side will be described as the rear side.

The main housing 110 may be formed in a cup cross-sectional shape with a front end opened and a rear end partially closed. An inverter housing 210, which will be described later, may be coupled to the open front end of the main housing 110 and sealed, and a frame part 112 supporting the compression unit 105 may integrally extend from the closed rear end of the main housing 110. A first shaft accommodating portion 113 through which a main bearing portion 132 of the rotating shaft 130 which will be described later penetrates and is rotatably supported may be formed at the frame part 112 of the main housing 110 and may have a cylindrical shape.

A first bearing 171 which may be formed as a bush bearing may be inserted and coupled into the first shaft accommodating portion 113, and an inner circumferential surface of the first shaft accommodating portion 113 may be separated from the main bearing portion 132 of the rotating shaft 130 so that the back pressure chamber S3 may communicate with the motor chamber S1. An intake port 111 to which an suction pipe (not shown) may be connected may be formed near a front end of the main housing 110, so that the motor chamber S1 of the disclosed exemplary embodiment may form a kind of suction space. Accordingly, the motor operated compressor according to the disclosed exemplary embodiment may form a low-pressure compressor as the refrigerant is sucked into the compression unit through the internal space of the main housing constituting the motor chamber.

In the main housing according to the disclosed exemplary embodiment, the frame part may be integrally formed as described above. Accordingly, it may be possible to eliminate the process of separately assembling the frame to the main housing, thereby reducing the number of assembling steps and enhancing assembling performance of the driving motor.

The driving motor 120 may include a stator 121 inserted and fixed to the inner circumferential surface of the main housing 110 and a rotor 122 disposed inside the stator 121 and rotated by an interaction with the stator 121. A rotating shaft 130 which rotates with the rotor 122 to transmit a rotational force of the driving motor 120 to the compression unit 105 may be coupled to the rotor 122.

The stator 121 may be fixed to the main housing 110 by shrinkage-fitting (or warn shrink-fitting) a stator core 1211. Accordingly, when the stator 121 has a small insertion depth in the main housing 110, an assembling operation may be facilitated and concentricity of the stator 121 may be maintained in the process of shrinkage-fitting the stator 121.

At the center of the rotor 122, the rotating shaft 130 may be coupled to the rotor core 1221 by shrinkage-fitting (or warn shrink-fitting). The rotating shaft 130 may support both ends in the radial direction with the driving motor 120 therebetween. However, as in the disclosed exemplary embodiment, one end of the rotating shaft 130 may be a fixed end supported at two points in the radial direction at one side of the driving motor 120, that is, the frame part 112 and the fixed scroll 150, and the other end of the rotating shaft 130 coupled to the rotor 122 of the driving motor 120 may be a free end in the radial direction.

The rotating shaft 130 may include a shaft portion 131 coupled to the rotor 122, a main bearing portion 132 rotatably supported in the first shaft accommodating portion 113 in the radial direction, an eccentric portion 133 eccentrically coupled to an orbiting scroll 140, and a sub-bearing portion 134 rotatably supported in a second shaft accommodating portion 157 of the fixed scroll 150 in the radial direction. The main bearing portion 132 and the sub-bearing portion 134 may support the rotating shaft 130 in the radial direction as described above and the eccentric portion 133 may transmit the rotational force of the driving motor 120 to the orbiting scroll 140 so that the orbiting scroll 140 may perform an orbiting motion via an Oldham ring 180.

In addition, referring to FIG. 3, an axial bearing protrusion portion 135 may extend radially in the middle of the rotating shaft 130, that is, between the main bearing portion 132 and the eccentric portion 133. The axial bearing surface 135 a of the axial bearing protrusion portion 135 may form a thrust surface with the axial bearing surface 113 a of the first shaft accommodating portion 113.

Inside the rotating shaft 130, an oil supply guide flow path 136 may be formed as an elongated passageway extending by a predetermined depth from the rear end to the front end of the rotating shaft 130. Oil supply holes 137 a, 137 b, and 137 c may be formed in the middle of the oil supply guide flow path 136 and toward an outer circumferential surface of the sub-bearing portion 134, the eccentric portion 133, and the sub-bearing portion 134, respectively. This will be explained later with an oil supply structure.

The compression unit 105 may include the orbiting scroll (or a first scroll) 140 that may be supported on the frame part 112 in an axial direction and performing an orbiting motion and the fixed scroll (or a second scroll) 150 that may be engaged with the orbiting scroll 140 and fixed and coupled to a rear end of the frame part 112. Between the orbiting scroll 140 and the fixed scroll 150, a pair of two compression chambers V may be formed when the orbiting scroll 140 performs an orbiting motion.

The orbiting scroll 140 may be axially supported on the rear surface of the frame part 112. An Oldham ring 180 may be provided between the frame part 112 and the orbiting scroll 140 as a rotation preventing mechanism configured to prevent rotation of the orbiting scroll 140. The Oldham ring 180 may be inserted into an Oldham ring seating recess (not shown) of the frame part 112, and the rotation preventing mechanism may also include a method of a pin and a ring, as well as the Oldham ring.

In the orbiting scroll 140, an orbiting scroll disk plate portion (hereinafter, referred to as orbiting disk plate portion) 141 may have a substantially disc shape, and an orbiting wrap 142 may engage with a fixed wrap 153, which will be described later, to form the compression chamber V on an inner surface and an outer surface with respect to the fixed wrap 153 may be formed on a front side of the orbiting disk plate portion 141.

A back pressure hole 141 a allowing the back pressure chamber S3 and the intermediate compression chamber V to communicate with each other may be formed at the orbiting disk plate portion 141. Accordingly, oil or the refrigerant may flow between the back pressure chamber S3 and the intermediate compression chamber according to a difference between a pressure of the back pressure chamber S3 and the intermediate compression chamber.

A rotating shaft coupling portion 143 through which the eccentric portion 125 d of the rotating shaft 125 is rotatably coupled may be formed to penetrate through the center of the orbiting disk plate portion 141. The rotating shaft coupling portion 143 may be formed in a cylindrical shape and a third bearing 173 forming a bearing surface with an eccentric portion 125 d of the rotating shaft 125 may be inserted and coupled to the inside of the rotating shaft coupling portion 143. The rotating shaft coupling portion (or third bearing) 143 may be formed to overlap the orbiting wrap 142 in a radial direction and the rotating shaft coupling portion 143 may form a portion of the orbiting wrap 142 at a radially innermost location.

The fixed scroll 150 may be coupled to the rear surface of the frame part 112 from the outside of the main housing 110 as described above. In this case, a sealing member such as an O-ring or a gasket may be provided between the frame part 112 and the fixed scroll 150.

In the fixed scroll 150, a fixed scroll disk plate portion (hereinafter, referred to as a fixed disk plate portion) 151 may be formed in a substantially disk shape, and a scroll sidewall portion 152 coupled to a rear side support surface (referred to as a support surface) 130 a of the frame may be formed at an edge of a front side of the fixed disk plate portion 151.

The scroll sidewall portion 152 may be formed in an annular shape, the outer circumferential surface of the scroll sidewall portion 152 may form an outer wall of the fixed scroll 150, and a front surface 152 a of the scroll sidewall portion 152 may be coupled to the support surface 130 a of the frame part 112 with the sealing member 180 c, which will be described later, therebetween. The scroll sidewall portion will be described together with the sealing member.

A fixed wrap 153 which may be engaged with the orbiting wrap 142 to form the compression chamber may be formed on the front surface of the fixed disk plate portion 151. The fixed wrap 153 may be formed in an involute shape together with the orbiting wrap 142 but may be formed in various other shapes.

For example, when the rotating shaft 125 is coupled through the center of the orbiting scroll 140, a final compression chamber may be formed at an eccentric position and a significant pressure difference may be generated between the compression chambers. This is because, in the case of an axially penetrated scroll compressor, as the final compression chamber is formed eccentrically from the center of the scroll, the pressure of one compression chamber may be significantly lower than the pressure of the other compression chamber. Therefore, in the axially penetrated scroll compressor, it may be advantageous to form the orbiting wrap 142 and the fixed wrap 153 in a non-involute shape as in the disclosed exemplary embodiment.

The scroll sidewall portion 152 is formed with a scroll side suction hole 154 that communicates with a frame side suction hole 135 of the frame part 112 and guides the refrigerant to the suction chamber. Only one scroll side suction hole 154 may be formed when the fixed wrap 153 and the orbiting wrap 142 are asymmetric, but a plurality of scroll side suction holes may be formed when the fixed wrap 153 and the orbiting wrap 142 are symmetrical as in the disclosed exemplary embodiment.

At a central portion of the fixed disk plate portion 151, a discharge port 155 for allowing the final compression chamber V to communicate with the discharge chamber S2, which will be described later, and guiding discharge of the refrigerant may be formed. The discharge port 155 may be formed to penetrate from the compression chamber V toward the discharge chamber S3 in the axial or sloped direction of the fixed disk plate portion 151. Only one discharge port 155 may be formed to communicate with both the first compression chamber and the second compression chamber or a first discharge port and a second discharge port may be formed to independently communicate with the first compression chamber and the second compression chamber.

A discharge valve 156 for opening and closing the discharge port 155 may be provided on the rear surface of the fixed disk plate portion 151. The discharge valve 156 may be formed individually if there are a plurality of the discharge ports 155, or a plurality of discharge valves 156 may be integrally formed.

A second shaft accommodating portion 157 may be formed at the center of the fixed disk plate portion 151 so that the sub-bearing portion 125 c of the rotating shaft 125 may be rotatably inserted and supported in the radial direction. The second shaft accommodating portion 157 may extend in the axial direction from the fixed disk plate portion 151 toward the rear housing 160 or may be formed by increasing a thickness of the fixed disk plate portion 151. However, in the latter case, not only the weight of the fixed scroll 150 may increase but also an unnecessary portion may be formed to be thick, so that the length of the discharge port 155 may become long and a dead volume may increase. Therefore, it is preferable that the second shaft accommodating portion 157 is formed by protruding a part of the fixed disk plate portion 151 like the former in an axial direction from a portion excluding a portion where the discharge port 155 is formed, for example.

The second shaft accommodating portion 157 may be formed in a cylindrical shape in which a rear side is closed. A second bearing 172, which may forms a bearing surface with the sub-bearing portion 125 c of the rotating shaft 125, may be inserted and coupled to the inner circumferential surface. The second bearing 172 may be a bush bearing or a needle bearing.

An oil accommodating space 156 a extending in the axial direction than an end portion of the rotating shaft 130 may be formed in the rear side of the second shaft accommodating portion 157. The oil accommodating space 156 a may be located between a first oil supply guide flow path 157 a, which will be described later, and the oil supply guide flow path 136. The first oil supply guide flow path 157 a may communicate with the discharge chamber S2, and the oil supply guide flow path 136 may communicate with each bearing surface provided on outer circumferential surfaces of the main bearing portion 132, a sub-bearing portion 134, and the eccentric portion 133.

The first oil supply guide flow path 157 a may be formed at the fixed scroll 150 or at a rear housing 160 which will be described later. For example, when the first oil supply guide flow path 157 a is formed at the fixed scroll 150, a rear surface of the fixed scroll 150, that is, a surface facing the frame part 112, among both side surfaces of the fixed scroll 150 in the axial direction may be a first surface 150 a and an opposing surface of the first surface 150 a may be a second surface 150 b. An oil supply protrusion portion 157 protruding toward the rear housing 160 may be formed on the second surface 150 b and a first oil supply guide flow path 157 a may be formed at the oil supply protrusion portion 157. A decompression member 191, which will be described later, may be inserted into the first oil supply guide flow path 157 a, and the decompression member 191 may be supported by a stopper member 195 inserted into an inlet of the first oil supply guide flow path 157 a.

One end of the first oil supply guide flow path 157 a may communicate with the outer circumferential surface of the fixed disk plate portion 151 through an oil supply through hole 195 a which will be described later and the other end of the first oil supply guide flow path 157 a may communicate with an inner circumferential surface of an oil accommodating space 156 a.

Accordingly, the high-pressure oil separated from the refrigerant at the discharge chamber S2 of the rear housing 160 may quickly flow to the oil accommodating space 156 a along the first oil supply guide flow path 157 a due to a pressure difference, and the oil may be quickly supplied to each bearing surface through the oil supply guide flow path 136 and respective oil supply holes 137 a to 137 c due to a pressure difference. The first oil supply guide flow path will be described later together with a foreign material blocking portion.

Referring to FIG. 3 again, an oil supply guide flow path 136 and a plurality of oil supply holes 137 a, 137 b, and 137 c may be formed on the rotating shaft 130. As described above, the first oil supply guide flow path 136 may be formed in the axial direction, extending to a predetermined depth from an end portion of the rotating shaft 130, that is, in a direction from a rear end to a front end of the rotating shaft 130. An open end of the oil supply guide flow path 136 may be received in the oil accommodating space 156 a. The plurality of oil supply holes 137 a, 137 b, and 137 c may be formed at predetermined intervals along an axial direction in the middle of the first oil supply guide flow path 136.

The plurality of oil supply holes 137 a, 137 b and 137 c may include a second oil supply hole 137 b penetrating through the outer circumferential surface of the sub-bearing portion 134, a third oil supply hole 137 c penetrating through the outer circumferential surface of the eccentric portion 133, and a first oil supply hole 137 a penetrating through the outer circumferential surface of the main bearing portion 132.

The oil flowing into the first oil supply guide flow path 136 from the oil accommodating space 156 a may sequentially pass through the second oil supply hole 137 b, the third oil supply hole 137 c, and the first oil supply hole 137 a and may be supplied to each bearing surface.

The rear housing 160 may be coupled to the rear surface of the fixed scroll 150. The discharge chamber S2 may be formed on the front surface of the rear housing (160) together with the rear surface of the fixed scroll 150. The rear housing 160 may be provided with an exhaust port 161 communicating with the discharge chamber S2 to discharge the refrigerant discharged to the discharge chamber S2 and an oil separator (not shown) may be installed at the exhaust port 161.

The inverter housing 210 may be coupled to cover the opposite side of the main housing 110 among both ends of the main housing 110, that is, at the front end forming an opening end of the main housing 110.

Referring to FIGS. 1 to 3 again, the inverter housing 210 may constitute a part of the inverter module 201, and the inverter housing 210 may form an inverter chamber S4 with an inverter cover 220.

The inverter chamber S4 may accommodates an inverter component 230 such as a substrate and an inverter element, and the inverter housing 210 and the inverter cover 220 may be bolted together. The inverter cover 220 may be assembled to the inverter housing 210 after the inverter housing 210 is first assembled to the main housing 110, or after the inverter housing 210 and the inverter cover 220 are assembled first, the inverter housing 210 may be assembled to the main housing 110. The former and the latter may be classified according to a method of assembling the inverter housing 210 to the main housing 110.

Reference numeral 114 denotes a first protrusion portion, 114 a denotes a first flow path, 138 denotes a balance weight, 154 denotes a second protrusion portion, 154 a denotes a second flow path, and 162 denotes a support protrusion portion.

The motor operated compressor according to the disclosed exemplary embodiment may operate as follows.

When power is applied to the driving motor 120, the rotating shaft 130 may rotate together with the rotor 122 to transmit rotational force to the orbiting scroll 140. The orbiting scroll 140 may perform an orbiting motion via the Oldham ring 180. The compression chamber V may be continuously moved toward the center side and the volume may be decreased.

Refrigerant may flow into the motor chamber S1 which may be a suction space through the intake port 101 a. The refrigerant flowing into the motor chamber S may pass through a flow path formed on the outer circumferential surface of the stator 121 and the inner circumferential surface of the main housing 110 or via an air gap between the stator 121 and the rotor 122 and may be sucked into the compression chamber V through a suction flow path Fg provided at the main housing 110 and the fixed scroll 150.

The refrigerant may be compressed by the orbiting scroll 140 and the fixed scroll 150 and may be discharged to the discharge chamber S2 through the discharge port 155. The refrigerant may be separated from the oil in the discharge chamber S2. The refrigerant separated from the oil may be discharged to a refrigerating cycle through the exhaust port 161. The oil may be supplied in a mist state to the bearing surface through the first oil supply guide flow path 157 a, the oil accommodating space 156 a, the oil supply guide flow path 136, and the oil supply holes 137 a to 137 c constituting an oil supply passage. A portion of the oil may flow into the back pressure chamber S3 to form a back pressure, pushing the orbiting scroll 140 toward the fixed scroll 150.

The orbiting scroll 140 may be pushed in the direction toward the fixed scroll 150 by the back pressure of the back pressure chamber S3 to seal the compression chamber V between the orbiting scroll 140 and the fixed scroll 150. A part of the oil in the back pressure chamber S3 may flow into the compression chamber V through the back pressure hole 141 a provided in the orbiting disk plate portion 141, while a part of the oil may flow out to the motor chamber S1 through between the main bearing portion 132 and the first bearing 171 so that the back pressure chamber S3 may form a flow pressure as described above. This sequential process may be repeated.

In the motor operated compressor according to the present disclosure, as described above, the refrigerant oil in the mist state may be separated from the refrigerant in the discharge chamber and may flow into the oil receiving space provided in the second shaft accommodating portion through the first oil supply guide flow path. The refrigerant oil may be supplied to the bearing surface and the back pressure chamber respectively through the oil supply guide flow path of the rotating shaft and the oil supply holes.

As the refrigerant oil may form a high pressure corresponding to the discharge pressure, a pressure of the high-pressure refrigerant must be reduced to an intermediate pressure. The refrigerant at intermediate pressure must be supplied to each of the bearing surface and the back pressure chamber. If the high-pressure refrigerant oil corresponding to the discharge pressure is not decompressed to an appropriate pressure, a part of the refrigerant oil may flow into the compression chamber through the bearing surface. As a result, over-compression may occur in the compression chamber due to the high-pressure refrigerant oil and compression efficiency may be degraded. Further, a part of the refrigerant oil may flow into the back pressure chamber, excessively raising the pressure in the back pressure chamber. As a result, the orbiting scroll may be excessively brought into close contact with the fixed scroll and a friction loss may be increased.

Accordingly, in the disclosed exemplary embodiment, a decompression device may be provided. The decompression device may decompress the pressure of the refrigerant oil to an appropriate pressure before the refrigerant oil separated from the refrigerant in the discharge chamber may be supplied to the bearing surface. The decompression device according to the disclosed exemplary embodiment may be installed at the oil supply passage located on the upstream side of the bearing surface and the back pressure chamber. As a result, it may be possible to prevent the high-pressure refrigerant oil corresponding to the discharge pressure from flowing into the bearing surface or the back pressure chamber in advance.

FIG. 4 is an exploded perspective view of an exemplary decompression device shown in FIG. 3, and FIG. 5 is a cross-sectional view of the exemplary decompression device shown in FIG. 4.

Referring to FIGS. 4 and 5, the decompression device 190 according to the disclosed exemplary embodiment may include a decompression member 191 inserted into the first oil supply guide flow path 157 a that allows the discharge chamber S2 and the oil accommodating space 156 a to communicate with each other. The decompression member 191 may be formed of a fin member having a predetermined length and a sectional area. For example, decompression member 191 may be a rod having a predetermined length and cross-sectional area. The decompression device 190 according to the disclosed exemplary embodiment may use a sectional area of a decompression flow path 190 a formed between an outer circumferential surface of the decompression member 191 and an inner circumferential surface of the first oil supply guide flow path 157 a. A length of the decompression flow path 190 a may be defined by the length of the decompression member 191. The diameter and length of the decompression member 191 may be appropriately adjusted in consideration of a pressure difference between the discharge chamber S2 and the first oil supply guide flow path 157 a.

Both ends of the first oil supply guide flow path 157 a may be opened. A first end communicating with the discharge chamber S2 may form an oil supply inlet 1571 and a second end communicating with the oil accommodating space 156 a may form an oil supply outlet 1572. Also, a decompression member accommodating portion 1573 into which the decompression member 191 is inserted may be formed between the oil supply inlet 1571 and the oil supply outlet 1572.

As described above, a radial sectional area of the decompression member accommodating portion 1573 may be formed to be larger than a radial sectional area of the decompression member 191 so that a decompression flow path 190 a may be formed between an outer circumferential surface of the decompression member 191 and an inner circumferential surface of the decompression member accommodating portion 1573. Accordingly, the oil supply inlet 1571, the decompression member accommodating portion 1573, and the oil supply outlet 1572 may communicate with each other.

The oil supply inlet 1571, the decompression member accommodating portion 1573, and the oil supply outlet 1572 may be formed concentrically in the axial direction. However, when the oil supply inlet 1571, the decompression member accommodating portion 1573, and the oil supply outlet 1572 are formed concentrically, the oil supply inlet 1571 and the oil supply outlet 1572 may be blocked by the decompression member 191. In particular, since the discharge chamber S2 may form a high pressure relative to the oil accommodating space 156 a, the decompression member 191 may be pushed toward the oil accommodating space 156 a by the pressure of the discharge chamber S2 when the compressor is operated. Thus, when the length of the decompression member 191 is adjusted appropriately, the oil supply inlet 1571 may not be blocked by the decompression member 191, but the oil supply outlet 1572 may be blocked as decompression member 191 may be pushed by the pressure of the discharge chamber S2.

In view of this, in this embodiment, the oil supply outlet 1572 may be formed eccentrically with respect to the decompression member accommodating portion 1573. FIG. 6 is a cross-sectional view taken along line “V-V” in FIG. 5, and illustrates the relative positions of the oil supply outlet and the depressurization member accommodating portion.

Referring to FIG. 5 again, a axial center O′ of the oil supply outlet 1572 may be formed to be further moved toward the rear side, that is, toward the rear housing 160, relative to an axial center O of the decompression member accommodating portion 1573. Accordingly, as illustrated in FIG. 6, the axial center O′ of the oil supply outlet 1572 may be formed to be eccentric by being spaced apart from the axial center O of the decompression member accommodating portion 1573 by a predetermined distance t.

The oil supply inlet 1571 may be located at a lower end of the decompression member accommodating portion 1573 and may be spaced apart from a bottom surface of the discharge chamber S2 by a predetermined distance. Since the decompression member 191 must be inserted through the oil supply inlet 1571, an inner diameter D1 of the oil supply inlet 1571 may be formed to be larger than or equal to an inner diameter D3 of the decompression member accommodating portion 1573. Accordingly, since the inner diameter D1 of the oil supply inlet 1571 may be formed to be larger than a diameter D4 of the decompression member 191, a release preventing member must be inserted into the oil supply inlet 1571 to block a part of the oil supply inlet 1571 to prevent the decompression member 191 from being detached. The release preventing member may be a stopper member 195 which may be press-fit or may be screw-coupled as illustrated in the figure. Although not shown, the release preventing member may also be formed as a pin member coupled to a side across the oil supply inlet 1571.

As illustrated in FIG. 5, when the release preventing member is the stopper member 195, at least one oil supply through hole 195 a may be formed to allow the refrigerant oil to flow into the decompression member accommodating portion 1573 from the discharge chamber S2. The oil supply through hole 195 a may be formed at the center or at the edge. However, an inner diameter D5 of the oil supply through hole 195 a may be formed to be smaller than the outer diameter D4 of the decompression member 191 so that the decompression member 191 may be not detached.

The inner diameter D1 of the oil supply inlet 1571 and the inner diameter D3 of the decompression member accommodating portion 1573 may be formed to be equal to each other. In this case, however, the stopper member 195 must be prevented from being pushed toward the decompression member accommodating portion 1573 by the pressure of the discharge chamber S2, for example, the stopper member 195 is press-fitted or screw-coupled into the oil supply inlet 1571. Thus, as illustrated in FIG. 5, the inner diameter D1 of the oil supply inlet 1571 may be preferably formed to be larger than the inner diameter D3 of the decompression member accommodating portion 1573 so that the oil supply inlet 1571 serves as a kind of stopper member mounting recess.

When the axial center of the oil supply outlet 1572 is formed eccentrically with respect to the axial center of the decompression member 191 as described above, even though the decompression member 191 is placed to be free in the decompression member accommodating portion 1573, the outlet 1572 may be significantly less likely to be clogged by the decompression member 191.

Referring again to FIG. 5, an axial length L1 of the decompression member accommodating portion 1573 may be formed to be larger than an axial length L2 of the decompression member 191. Accordingly, the decompression member 191 may freely move up and down in the decompression member accommodating portion 1573.

FIG. 7A is a schematic view illustrating a position of the decompression member 191 during an operation in the decompression device according to FIG. 5, and FIG. 7B is a cross-sectional view taken along line “VI-VI” in FIG. 7A.

For example, when the compressor is stopped, the pressure in the discharge chamber S2 may be equal to the pressure in the oil accommodating space 156 a, so that the decompression member 191 may be lowered by weight and placed on the stopper member 195.

Thereafter, when the compressor is operated and the discharge chamber S2 is filled with the refrigerant oil, the decompression member 191 may be pushed up toward the upper side, that is, toward the oil supply outlet 1572 by the refrigerant oil. Although the decompression member 191 may block the oil supply outlet 1572, the axial center O′ of the oil supply outlet 1572 may be formed eccentrically with respect to the axis O of the decompression member accommodating portion 1573, so that the refrigerant oil may move from the decompression flow path 190 a toward the oil supply outlet 1572. Then, as illustrated in FIGS. 7A and 7B, the refrigerant oil in the decompression member accommodating portion 1573 may be pushed toward the oil supply outlet 1572 (right side in the figure) around the decompression member 191 when projected in the radial direction, and pushes the decompression member 191 to the opposite radial direction (left side in the figure) to secure the decompression flow path 190 a. Then, the decompression flow path 190 a and the oil supply outlet 1572 may be always opened, so that the refrigerant oil in the discharge chamber S2 may smoothly flow into the oil accommodating space 156 a.

Accordingly, in this embodiment, even when the decompression member 191 is placed in a free state to be movable in the axial direction within the decompression member accommodating portion 1573, the decompression member 191 may be prevented from blocking the decompression flow path 190 a, that is, the oil supply outlet 1572. The refrigerant oil may be reduced in pressure while passing through the decompression device, and may be smoothly supplied to the bearing surface, the compression chamber, and the back pressure chamber. As a result, the refrigerant oil may be quickly and stably supplied to the corresponding portion, thereby improving reliability and compression efficiency of the compressor.

In addition, in the disclosed exemplary embodiment, since the decompression flow path 190 a may be formed by inserting the decompression member 191 into the first oil supply guide flow path 157 a, the length of the decompression member 191 and the sectional area of the decompression flow path 190 a may be easily adjusted, while the decompression flow path 190 a may be formed to be short and simple, thus enhancing a decompression effect.

Further, as the decompression flow path 190 a may be formed only at the fixed scroll 150, a machining error or an assembly error of the decompression flow path 190 a may be reduced, thereby preventing the sectional area of the decompression flow path 190 a from being excessively narrowed, thus easily adjusting the degree of decompression and making pressure dispersion uniform.

Further, since the inlet and the outlet of the oil supply guide flow path may be formed on both sides of the decompression member 191 in the length direction, the effective length of the decompression flow path 190 a may be uniformly secured. Thus, as the decompression effect is uniformly maintained, the pressure in the back pressure chamber S3 may be formed to be constant, and by stabilizing the behavior of the orbiting scroll, leakage between the compression chambers may be prevented and the compression loss may be suppressed.

In the disclosed exemplary embodiment, as the decompression flow path 190 a is formed by inserting the decompression member 191 into the first oil supply guide flow path 157 a, the orbiting scroll 140 or the fixed scroll 150 may be easily machined as compared to when the decompression flow path 190 a is formed by penetrating through the wrap of the orbiting scroll 140 or the disk plate portion of the fixed scroll 150 in the axial direction. This may allow the refrigerant oil to flow smoothly between the two scrolls, thus increasing reliability between the two scrolls.

Further, since the decompression flow path 190 a may be formed separately from the compression chamber V, it may be possible to prevent the refrigerant oil from flowing back to the compression chamber V through the decompression flow path 190 a.

Further, in this embodiment, since the decompression flow path 190 a may be formed in front of the oil accommodating space 156 a in which the rotating shaft 130 is accommodated, an axial load applied to the rotating shaft 130 in the axial direction may be reduced. This may prevent the rotating shaft 130 from being exposed to the discharge pressure, thereby reducing the axial load applied to the rotating shaft 130, extending a service life of the bearing supporting the rotating shaft 130 in the axial direction, and reducing a friction loss.

In the disclosed exemplary embodiment, the decompression member 191 may be freely placed in the decompression member accommodating portion 1573, but the decompression member 191 may be fixed and coupled to the decompression member accommodating portion 1573. FIG. 8 is a cross-sectional view showing another exemplary embodiment of a decompression member according to FIG. 3, and FIG. 9 is a cross-sectional view taken along line “VII-VII” in FIG. 8.

Referring to FIGS. 8 and 9, the axial length L1 of the decompression member accommodating portion 1573 may be the same as the axial length L2 of the decompression member 191. Thus, an upper end of the decompression member 191 may be in close contact with a step surface 1573 a formed between the second end and oil supply outlet 1572 of the decompression member accommodating portion 1573, while a lower end of the decompression member 191 may be in close contact with the upper surface of the stopper member 195 coupled to the oil supply inlet 1571 and supported.

The decompression member 191 may be formed in a circular cross-sectional shape like the decompression member accommodating portion 1573 and the diameter of the decompression member 191 may be smaller than the inner diameter of the decompression member accommodating portion 1573. The decompression member 191 may be eccentrically coupled to the decompression member accommodating portion 1573. Accordingly, the decompression flow path 190 a may be formed between the outer circumferential surface of the decompression member 191 and the inner circumferential surface of the decompression member accommodating portion 1573.

The basic configuration and the operation and effect of the decompression device according to the disclosed exemplary embodiment may be similar to those of the above-described embodiment. However, when the axial length L2 of the decompression member 191 and the axial length L1 of the decompression member accommodating portion 1573 are formed to be equal to each other so that both ends of the decompression member 191 are fixed as in this embodiment, the decompression member 191 may not be fixed at a desired position. This may occur due to a machining error or an assembly error and may excessively block the oil supply outlet 1572. In this case, the sectional area of the oil supply outlet 1572 communicating with the decompression flow path 190 a may not be sufficiently secured and an oil supply state may be poor.

In view of this, a decompression member supporting portion may be formed at the second end, which may be the upper end of the decompression member accommodating portion 1573. The decompression member supporting portion may be formed such that an axial center thereof may be eccentric with respect to the axial center of the oil supply outlet 1572. FIG. 10 is a cross-sectional view showing another embodiment of a decompression member according to FIG. 3, and FIG. 11 is a cross-sectional view taken along line “VIII-VIII” in FIG. 10.

Referring to FIGS. 10 and 11, the axial center O″ of the decompression member supporting portion 1574 may be eccentric from the axial center O′ of the oil supply outlet 1572. The decompression member support portion 1574 may be formed to be eccentric in a direction in which the axial center O of the decompression member accommodating portion 1573 may be eccentric from the axial center O′ of the oil supply outlet 1572. That is, the axial center O″ of the decompression member supporting portion 1574 may be located on a straight line on the opposite center of the axial center O′ of the oil supply outlet 1572 based on the axial center O of the decompression member accommodating portion 1573.

The basic configuration and the operation and effect of the decompression device according to the disclosed exemplary embodiment may be similar to those of the above-described embodiment. However, when the decompression member supporting portion 1574 is further formed between the decompression member accommodating portion 1573 and the oil supply outlet 1572 as in the disclosed exemplary embodiment, a kind of communication space may be formed between the decompression member accommodating portion 1573 and the oil supply outlet 1572. Thus, even though the decompression member 191 may not be fixed to a desired position due to a machining error or an assembling error, the decompression flow path 190 a and the oil supply outlet 1572 may be prevented from being excessively blocked by the communication space so as to be advantageous for securing the decompression flow path 190 a.

Another exemplary embodiment of the oil supply outlet and the decompression member accommodating portion in the decompression device of the motor operated compressor according to the present disclosure will be described.

That is, in the above-described embodiment, the oil supply outlet is formed to be eccentric with respect to the decompression member accommodating portion to prevent the oil supply outlet from being blocked. In the following exemplary embodiment, the oil supply outlet 1572 may be prevented from being blocked although it may be formed to be concentric with respect to the decompression member accommodating portion 1573.

In this case, the oil supply outlet 1572 may be easily formed. However, as described above, when the oil supply outlet 1572 is formed to be concentric with the decompression member accommodating portion 1573, the decompression member 191 may block the oil supply outlet 1572, when it moves freely in the decompression member accommodating portion 1573. Therefore, in this case, it is important to prevent the decompression member 191 from blocking the oil supply outlet 1572.

FIG. 12 is a cross-sectional view showing an exemplary embodiment of a decompression device according to the present disclosure, and FIG. 13 is a cross-sectional view taken along line “IX-IX” of FIG. 12.

Referring to FIGS. 12 and 13, the axial center O′ of the oil supply outlet 1572 may be formed to be concentric with the axial center O of the decompression member accommodating portion 1573. Even in this case, the inner diameter D2 of the oil supply outlet 1572 may be formed to be smaller than the inner diameter D3 of the decompression member accommodating portion 1573.

The decompression member 191 may be inserted and fixed to the inner circumferential surface of the decompression member accommodating portion 1573. However, in this case, the decompression flow path 190 a may be formed through a central portion of the decompression member 191 in the axial direction. The decompression flow path 190 a may be formed to be concentric with the oil supply outlet 1572 and the inner diameter of the decompression flow path 190 a may be formed to be smaller than or equal to the inner diameter of the oil supply outlet 1572.

Further, the decompression member 191 may be formed to be short in consideration of workability of the decompression flow path 190 a, but it may be advantageous to form the effective length of the decompression flow path as long as possible in consideration of a decompression effect. Therefore, it is advantageous to form the length L2 of the decompression member 191 to be about equal to the length L1 of the decompression member accommodating portion 1573. However, as described above, it may be formed of a member which may be easily machined, that is, a material having a hardness lower than that of the fixed scroll 150, such as plastic, in consideration of workability of the decompression flow path 190 a.

As described above, when the decompression flow path 190 a is formed at the center of the decompression member 191 and fixed to the decompression member accommodating portion 1573, the decompression member accommodating portion 1573 and the oil supply outlet 1572 may be formed to be concentric. In this case, the decompression member accommodating portion 1573 or the oil supply outlet 1572 may be easily machined.

Further, since the decompression member 191 may be inserted and fixed in the decompression member accommodating portion 1573, the stopper member for supporting the decompression member may be eliminated, thereby reducing the number of components and the number of assembly steps and reducing the manufacturing cost. Of course, although not shown in the drawing, the decompression member 191 may be supported by a separate stopper member or a fixing member when the decompression member 191 is inserted into the decompression member accommodating portion 1573.

FIG. 14 is a cross-sectional view showing another exemplary embodiment for fixing a decompression member in a decompression device according to the present disclosure, and FIG. 15 is a cross-sectional view taken along the line “X-X” in FIG. 14. Referring to FIGS. 14 and 15, the decompression member 191 may have a support protrusion portion 191 a extending radially at one end thereof. A support recess portion (or oil supply inlet) 1573 b may extend radially at the first end of the decompression member accommodating portion 1573 such that the support protrusion portion 191 a may be axially supported.

The support protrusion portion 191 a may be formed to be concentric with the axial center of the decompression member 191 and the support recess portion 1573 b is formed to be concentric with the axial center of the decompression member accommodating portion 1573 to correspond to the support protrusion portion 191 a. Accordingly, a communicating flow path 1573 c may be formed at one side of the support protrusion portion 191 a in the radial direction and spaced apart from the inner circumferential surface of the support recess portion (or the oil supply inlet) 1573 to communicate with the decompression flow path 190 a.

The support protrusion portion 191 a may be formed in a circular shape as shown in FIG. 15, but it may be formed in a rectangular shape in some cases. The support recess portion 1573 b may be formed in the same shape as the support protrusion portion 191 a. However, the communicating flow path 1573 c may be formed at one side of the support recess portion 1573 b in the radial direction, so that the discharge chamber S2 may communicate with the decompression flow path 190 a.

Further, the length L2 of the decompression member 191 may be shorter than the length L1 of the decompression member accommodating portion 1573. Accordingly, the oil supply outlet 1572 and an end portion of the decompression member 191 facing the oil supply outlet 1572 are spaced from each other to form a communicating space to allow the decompression flow path 190 a and the oil supply outlet 1572 to communicate with each other.

However, although not shown, the length L2 of the decompression member 191 may be formed to be equal to the length L1 of the decompression member accommodating portion 1573, and a communicating recess may be formed to be stepped or slantingly at an end portion of the decompression member L2 facing the oil supply outlet 1572. In this case, the communicating recess may form a kind of communicating space.

The basic configuration and the operation and effect of the decompression device according to the disclosed exemplary embodiment may be similar to those of the above-described embodiment. However, in case that the support protrusion portion 191 a is formed at the decompression member 191 to restrict movement in the axial direction, a communicating space 190 b may be secured such that the end portion of the decompression member 191 may be spaced apart from the oil supply outlet 1572 by a predetermined interval. Accordingly, even when the decompression member accommodating portion 1573 and the oil supply outlet 1572 may be formed to be concentric, a space between the decompression flow path 190 a and the oil supply outlet 1572 may be prevented from being blocked by the communicating space 190 b.

Meanwhile, the decompression device 190 according to the present disclosure may be configured such that the decompression member 191 may freely move inside the decompression member accommodating portion 1573 even though the decompression member accommodating portion 1573 and the oil supply outlet 1572 may be formed to be concentric. FIG. 16 is a cross-sectional view showing an embodiment in which a decompression member is free in a decompression device according to the present disclosure, and FIG. 17 is a cross-sectional view taken along line “XI-XI” in FIG. 16.

Referring to FIGS. 16 and 17, the axial center O of the decompression member accommodating portion 1573 and the axial center O′ of the oil supply outlet 1572 may be formed to be concentric, the length L2 of the decompression member 191 may be formed to be shorter than the length L1 of the decompression member accommodating portion 1573, and the outer diameter D4 of the decompression member 191 may be formed to be smaller than the inner diameter D3 of the decompression member accommodating portion 1573. Accordingly, the decompression flow path 190 a may be formed between the outer circumferential surface of the decompression member 191 and the inner circumferential surface of the decompression member accommodating portion 1573.

In this case, since the decompression member 191 is arranged in a free state inside the decompression member accommodating portion 1573, when the decompression member 191 is pushed up toward the second end of the decompression member accommodating portion 1573, the oil supply outlet 1572 may be blocked. Accordingly, in this embodiment, a communicating space portion 191 b may be formed at an end portion of the decompression member 191 facing the oil supply outlet 1572.

The communicating space portion 191 b may be formed as an inclined surface inclined in a direction toward the oil supply outlet 1572 as shown in the figure or may be formed as a stepped surface although not shown in the figure.

The basic configuration and the operation and effect of the decompression device according to the disclosed exemplary embodiment may be similar to those of the above-described embodiment. However, when the communicating space portion 191 b is formed at the end portion of the decompression member 191 as in the disclosed exemplary embodiment, even though the decompression member 191 is placed in a free state in the decompression member accommodating portion 1573 as the decompression member accommodating portion 1573 and the oil supply outlet 1572 are formed to be concentric, the decompression member 191 may be prevented from blocking the oil supply outlet 1572 due to the communicating space portion 191 b.

Another exemplary embodiment of the oil supply passage in the motor operated compressor according to the present disclosure is described below.

In the above-described embodiments, when the oil supply inlet 1571 constituting the inlet of the first oil supply guide flow path 157 a is formed to have the same inner diameter as the decompression member accommodating portion 1573 or the stopper member 195 is inserted, one or a plurality of oil supply holes 195 a may be formed in the stopper member 195. However, in the above-described embodiments, the inner diameter of the oil supply inlet 1571, that is, the radial sectional area of the oil supply inlet 1571 may be larger than the radial sectional area of the decompression flow path 190 a.

A foreign material mixed in the refrigerant oil may flow from the discharge chamber S2 to the decompression flow path 190 a through the oil supply inlet 1571 and block the decompression flow path 190 a or pass through the decompression flow path 190 a to flow into the bearing surface or the compression chamber to wear the bearing surface or the compression chamber.

Accordingly, in this exemplary embodiment, the foreign material blocking member may be provided in the oil supply inlet 1571. The foreign material blocking member may be a simple filter such as a mesh. However, when the mesh is installed, flow resistance to the refrigerant oil may increase and the suction amount of the refrigerant oil may decrease. FIG. 18 is a cross-sectional view showing a foreign material blocking member provided at the oil supply inlet in the motor operated compressor according to the present disclosure.

Referring to FIG. 18, the foreign material blocking member 196 according to the disclosed exemplary embodiment may be formed using a stopper member installed at the oil supply inlet 1571. A plurality of oil supply through holes 196 a may be formed at the foreign material blocking member 196 and the plurality of oil supply through holes 196 a may be formed in parallel in the same direction, that is, the axial direction. A sectional area of each of the oil supply through holes 196 a may be smaller than or equal to the sectional area of the decompression flow path 190 a.

In the other embodiments described above, for example, in the embodiment in which the decompression member 191 is inserted and fixed in the decompression member accommodating portion 1573 so that a separate stopper member is not installed, the foreign material blocking member illustrated in FIG. 18 may be installed. However, the foreign material blocking member 196 in this case may be formed of a thin plate member and may be fastened with a screw or a bolt in a state where it is in close contact to cover the first end of the decompression member accommodating portion 1573. Also in this case, a plurality of fuel supply through holes 196 a may be formed at the foreign material blocking member 196 in the same direction.

When the foreign material blocking member 196 is installed as described above, a foreign material may be prevented from flowing into the decompression flow path 190 a, thereby preventing the decompression flow path 190 a from being blocked, or a foreign material may be suppressed from flowing to the bearing surface or the compression chamber to wear the bearing surface of the compression chamber, thus enhancing reliability.

Another exemplary embodiment of an installation position of a decompression device in a motor operated compressor is described next. That is, in the above-described embodiment, the decompression device is provided at the fixed scroll, but in the disclosed exemplary embodiment, the decompression device may be formed at the rear housing. FIG. 19 is a cross-sectional view showing an embodiment in which the decompression device according to the disclosed exemplary embodiment is installed at the rear housing.

Referring to FIG. 19, a shaft receiving portion 162 may protrude toward the fixed scroll 150 on the front surface of the rear housing 160 and an oil supply protrusion portion 163 may be formed to elongate at a lower end of the shaft receiving portion 162 in a radial direction.

Further, an oil accommodating space 162 a may be formed inside the shaft receiving portion 162, a first oil supply guide flow path 163 a may be formed at the oil supply protrusion portion 163, and the decompression member 191 described above may be inserted into the first oil supply guide flow path 163 a.

The configuration in which the first oil supply guide flow path 163 a may include the oil supply inlet 1631, the oil supply outlet 1632 and the decompression member accommodating portion 1633 and the configuration in which the decompression member 191 is inserted into the first oil supply guide flow path 163 a according to this embodiment may be the same as that of the above-described embodiments. Therefore, detailed description thereof will be omitted. However, when the oil supply passage and the decompression device are provided in the rear housing as in the disclosed exemplary embodiment, the fixed scroll may be simply machined. Accordingly, it is possible to simplify machining for the fixed scroll, which requires a relatively high accuracy as compared with the rear housing, and reduce a machining error of the fixed scroll.

The foregoing embodiments are merely illustrative to practice the motor operated compressor according to the present disclosure. Therefore, the present disclosure is not limited to the above-described embodiments, and it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present disclosure. 

What is claimed is:
 1. A motor operated compressor comprising: a housing having a motor chamber; a driving motor located in the motor chamber of the housing; a first scroll; a second scroll coupled to the first scroll, the second scroll forming a compression chamber together with the first scroll; a rotating shaft coupled to a rotor of the driving motor, the rotating shaft extending through the first scroll and the second scroll in an axial direction and being eccentrically coupled to the first scroll; a rear housing forming a discharge chamber together with the second scroll; a shaft receiving portion included in one of the second scroll or the rear housing, the shaft receiving portion configured to support the rotating shaft in a radial direction; an oil supply guide flow path included in one of the second scroll or the rear housing, the oil supply guide flow path connecting the discharge chamber and the shaft receiving portion; and a decompression member inserted into the oil supply guide flow path, the decompression member configured to reduce a pressure of a fluid passing through the oil supply guide flow path.
 2. The motor operated compressor of claim 1, wherein an oil supply protrusion portion extends in the radial direction from the shaft receiving portion, and the oil supply guide flow path extends through the oil supply protrusion portion in the radial direction.
 3. The motor operated compressor of claim 2, wherein the oil supply guide flow path includes first and second open ends, the first end communicating with the discharge chamber and forming an oil supply inlet and the second end communicating with the shaft receiving portion and forming an oil supply outlet, a decompression member accommodating portion is formed between the oil supply inlet and the oil supply outlet, the decompression member is inserted into the decompression member accommodating portion, a cross-sectional area of the decompression member accommodating portion is larger than a cross-sectional area of the decompression member, a decompression flow path being disposed between an outer circumferential surface of the decompression member and an inner circumferential surface of the decompression member accommodating portion, and the oil supply inlet, the decompression member accommodating portion, and the oil supply outlet communicate with each other.
 4. The motor operated compressor of claim 3, wherein the oil supply outlet is eccentric with respect to the decompression member accommodating portion.
 5. The motor operated compressor of claim 4, wherein an axial length of the decompression member accommodating portion is larger than or equal to an axial length of the decompression member.
 6. The motor operated compressor of claim 5, wherein a decompression member support portion configured to support the decompression member in the axial direction is disposed between the oil supply outlet and the first end of the decompression member accommodating portion, and a longitudinal axis of the decompression member support portion is eccentric with respect to a longitudinal axis of the oil supply outlet.
 7. The motor operated compressor of claim 3, wherein the oil supply outlet is concentric with the oil supply inlet in the axial direction.
 8. The motor operated compressor of claim 7, wherein the decompression member is inserted into and coupled with the decompression member accommodating portion.
 9. The motor operated compressor of claim 8, wherein a decompression passage extends along the axial direction through a central portion of the decompression member, the decompression passage configured to communicate with the oil supply outlet.
 10. The motor operated compressor of claim 9, wherein the decompression member includes a material having hardness lower than the decompression member accommodating portion.
 11. The motor operated compressor of claim 8, wherein a support protrusion portion extends in a radial direction from one end of the decompression member, the decompression member accommodating portion includes a support recess portion configured to support the support protrusion portion in the axial direction, the support recess portion being located adjacent to the oil supply inlet, and the oil supply outlet and an end portion of the decompression member facing the oil supply outlet are spaced apart from each other to form a communicating space allowing the decompression flow path and the oil supply outlet to communicate with each other.
 12. The motor operated compressor of claim 7, wherein a communicating space portion is formed toward the oil supply outlet at an end portion of the decompression member facing the oil supply outlet.
 13. The motor operated compressor of claim 1, wherein the oil supply guide flow path includes a foreign material blocking member configured to block a foreign material, and the foreign material blocking member includes a plurality of oil supply through holes.
 14. The motor operated compressor of claim 13, wherein the foreign material blocking member is located adjacent to the discharge chamber.
 15. The motor operated compressor of claim 14, wherein a sectional area of at least one of the oil supply through holes is smaller than or equal to a sectional area between an inner circumferential surface of the oil supply guide flow path and an outer circumferential surface of the decompression member.
 16. A motor operated compressor comprising: an orbiting scroll; a fixed scroll coupled to the orbiting scroll and forming a compression chamber; a rotating shaft extending through the orbiting scroll and the fixed scroll, the shaft being rotatably coupled to the orbiting scroll; a shaft receiving portion included in one of the fixed scroll or a housing coupled to the fixed scroll, the shaft receiving portion being configured to support the rotating shaft in a radial direction; an oil supply guide flow path radially penetrating through a side wall surface of the shaft receiving portion and communicating with the shaft receiving portion; and a decompression member inserted into the oil supply guide flow path, wherein different portions of the oil supply guide flow path have longitudinal axes disposed eccentrically relative to teach other.
 17. The motor operated compressor of claim 16, wherein the decompression member is coupled to the oil supply guide flow path and fixed in the axial direction.
 18. The motor operated compressor of claim 16, wherein a decompression flow path is formed inside the decompression member.
 19. A motor operated compressor comprising: a housing extending from a front end to a rear end; a motor positioned within the housing; a fixed scroll positioned between the motor and the rear end; an orbiting scroll positioned between the motor and the fixed scroll, the orbiting scroll being configured to engage with the fixed scroll to form a compression chamber rear end; a shaft coupled to the motor at one end, the shaft being eccentrically coupled to the orbiting scroll, an opposite end of the shaft being received in a shaft receiving portion of the second scroll; a discharge chamber formed between the fixed scroll and the rear end of the housing; an oil supply guide flow path connecting the discharge chamber and the shaft receiving portion; and a decompression rod positioned concentrically within the oil supply guide flow path.
 20. The motor operated compressor of claim 19, further including a decompression flow path extending axially through the decompression rod, the decompression flow path forming at least a portion of the oil supply guide flow path. 